Before you attempt this configuration, you need to gather this
information from the ISDN service provider:

The ISDN switch type

ISDN Service Profile Identifiers (SPIDs) and Local Directory Numbers
(LDNs), where applicable. In North America, SPIDS are required for all ISDN
switch types except for 5ESS custom point-to-point. The LDN is the local
seven-digit ISDN phone number (no area codes) of your router. LDNs are required
for DMS-100.

You also need to gather this network information:

The Point-to-Point Protocol (PPP) hostname - You must assign a PPP
client name to both devices.

The PPP authentication type - Challenge Handshake Authentication
Protocol (CHAP) authentication is preferred and is used in this example.

This document is not restricted to specific software and hardware
versions.

The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.

Dialer profiles allow the configuration of physical interfaces to be
separated from the logical configuration required for a call. With dialer
profiles, the logical and physical configurations are dynamically bound on a
per-call basis.

Note: You cannot bridge on one B channel and route on the other channel.